Hot-air furnace



(No Model.) 1. D. SMEAD.

HOT AIR FURNACE.

Patented Sept. 22, 18

5:: 0 7 I j 0 0 C 0 c O UNTTED STATES PATENT l l lCE,

ISAAC D. SMEAD, or TOLEDO, OHIO.

HOT-AIR FURNACE.

SPECIFICATION forming part of Letters Patent No. 326,598, dated September 22, 1885. Application filed February 2 1, 1885. (No IllOtltLl T on whom it may concern:

Be it known that I, ISAAC D. SMEAD, of Toledo, in the county of Lucas and State of Ohio, have invented certain new and useful Improvements in Hot-AirFurnaees, of which the following is a specification.

My invention relates to hotair furnaces;

and the invention consists in the construction and manner of arranging and supporting the lining plates of the tire-box, as hereinafter more fully set forth.

Figure l is a longitudinal vertical section of the fire-box and aslrpit of the furnace. Fig.

2 is a transverse vertical section of the same,

looking from the rear toward the front; and Fig. 3 is a perspective view of one of the brackets, shown detached.

This invention is designed for use in con nection with the furnaces known as the Buttan heater, the general form of which is shown in Patent No. 289,865, granted to me December 11, 1883. In these heaters, as heretofore constructed, the fire-box was lined with castiron plates at the sides, which plates were perforated with a series of small holes distributed or located evenly over their entire surface at equidistant points, for the admission of air to mingle with the smoke and gas from the burning coal. These plates, in the former heaters, rested at their lower edges on a ledge or shoulder formed along each side of the fire-box at the top of the ash-pan, and at intervals along the sides of the ash-pan pockets or recesses were formed, through which the air was to pass from the ash-pit up behind the liningplates, and thence through the perforations in the plates to the fire. In practiee it is found that these pockets or recesses sooner or later became clogged with the ashes which work through the perforations and over the edge of the lining-plates, and thus prevent the air from passing up through them, as designed. It is also foundthatair entering through the perforations is not delivered in the best manner to mingle with and produce a perfect combustion of the gases; and my present invention is designed to overcome these difficulties or objections, and thereby to improve these heaters.

To accomplish these results, I make the ashpan B much deeper than heretofore and without any recesses or pockets in its side walls,

they being formed in a straight line from end to end, as shown in Figs. 1 and 2: I also dispense with the ledge along each side of the ash-pan on which the lining-plates formerly rested, and support the lining-plates 0 upon the brackets D, bolted to the sides of the ashpan B, as shown in Figs. 1 and 2, these brackets being made double, as shown at D, Fig. 1, at the points where two sections of the lining-plates meet near the front. The brackets D, as shown in Fig. 3, are made with a lateral flange, b, by which they can be securely bolted to the sides of the ash pan B, as shown in Fig. 2, and are provided at their extremity wit-h a hook shaped vertical projection 0, against which the lower edge of the liningplates 0 engage, and by which they are prevented from slipping off. As shown in Fig. 2, these brackets are made to project a considerable distance, so that when the plates 0 are set thereon, as shown in Fig. 2, there will be a clear space between their lower edges and the wall of the fire-box A of considerable width, it being in a full-sized furnace some three inches or more in width and extending the whole length of the fire-box on each side. The plates 0, as shown, have their upper edges curved outward, and rest against the walls of the fire-box, to which they are fitted closely, so as to prevent the air from passing directly up from behind them, and compel it to pass out laterally through the slots 0, as hereinafter more fully explained. By this construction it will be seen that a clear space or opening of considerable width is provided all along the bottom of the lining-plates 0, through which any ashes that get behind the lining-plates can drop at once into the ash-pan below, thus leaving a clear, open space all along for the air to pass from the ash-pit up behind the lining O, which cannot become obstructed. These lining-plates 0, instead of being perforated with a series of small holes, I construct with a series of slots 0, as shown in Figs. 1 and 2, they being arranged in two rows and made to overlap, as shown, so that the air is delivered in a thin sheet or sheets the entire length of the firebox. As the air passes through the ash-pit and is brought in contact with the heated plates 0, against which the burning fuel rests, it is heated, and therefore is in the best possible condition for mingling with and producing a more perfect conibustion of the gases arising from the burning coal, and by projecting it laterally through the slots 0, directly over or out the burning mass, it is thereby more effectually mingled with the hot gases and smoke. in the use of soft coal, for which this class of heaters is hind the side plates, 0, so that when the draft is closed in the ash-box air can. enter at the front of the fire-box under the plate 0, and pass from thence along behind the side plates, 0, there being the usual damper or slide, 12, arranged at the front for that purpose. As

shown in Fig. 1, this front plate,G, issupported by a cross-bar or plate, E, upon which the front ends of the grate-bars a also rest, thus leaving a passage or opening connecting the space under the front-plates, O, with the ashpit, so that air may pass freely from one to the other, according as the upper or lower draft may be closed, in whole or in part.

Having thut described my invention, what I claim is In combination with the fire-box A of a furnace, the brackets D and the lining-plates 0, provided with the horizontal slots 0, said plates having their upper edges arranged to fit closely against the inner walls of. the firebox and their lower edges set some distance from the side walls, substantially as shown and described.

ISAAC D. SMEAD.

Witnesses:

ARTHUR L. LEWIS, J s. A. VVILLs. 

